GATE PH kind:question PYQs & Answers — Page 11

Questions 101–110 of 650. Imported answers require independent review unless marked reviewed.

The screened nuclear charge of neutral Helium atom is given as

, where

is the magnitude of the electronic charge. Assuming the Bohr model of the atom for which the energy levels are

atomic units (

is the atomic number), the first ionization potential of Helium in atomic units is

Your answerChoose one option.

0.89

1.78

0.94

3.16

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The wire loop shown in the figure carries a steady current

. Each straight section of the loop has length

. A part of the loop lies in

plane and the other part is tilted at

with respect to the

plane. The magnitude of the magnetic dipole moment of the loop (in appropriate units) is

Your answerChoose one option.

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The figure shows a system of two equal masses

and three massless horizontal springs with spring constants

. Ignore gravity. The masses can move only in the horizontal direction and there is no dissipation. If

and

(all in appropriate units), the frequencies of the normal modes of the system in the same system of units are

Your answerChoose one option.

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Two projectile protons

and

both with spin up (along the +

direction) are scattered from another fixed target proton

with spin up at rest in the

plane, as shown in the figure. They scatter one at a time. The nuclear interaction potential between both the projectiles and the target proton is

, where

is the orbital angular momentum of the system with respect to the target,

is the spin angular momentum of the system and

is a negative constant in appropriate units. Which one of the following is correct?

Your answerChoose one option.

will be scattered in the +

direction (upward) and

will be scattered in the −

direction (downward)

will be scattered in the +

direction (upward) and

will be scattered in the +

direction (upward)

will be scattered in the −

direction (downward) and

will be scattered in the +

direction (upward)

will be scattered in the −

direction (downward) and

will be scattered in the −

direction (downward)

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A thin circular ring of radius

lies in the

plane with its centre coinciding with the origin. The ring carries a uniform line charge density

. The quadrupole contribution to the electrostatic potential at the point

, where

, is

Your answerChoose one option.

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particle is scattered from an Au target at rest as shown in the figure.

and

are the detectors to detect the scattered

particle at an angle

and along the beam direction, respectively, as shown. The signals from

and

are converted to logic signals and fed to logic gates. When a particle is detected, the signal is 1 and is 0 otherwise. Which one of the following circuits detects the particle scattered at the angle

only?

Your answerChoose one option.

Diagram for Physics question 41 (figure 2)

Diagram for Physics question 41 (figure 3)

Diagram for Physics question 41 (figure 4)

Diagram for Physics question 41 (figure 5)

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Consider a two-level system with energy states

and

. The number of particles at

level is

and the number of particles at

level is

. The total energy of the system is

and the total number of particles is

. In the thermodynamic limit, the inverse of the absolute temperature of the system is (Given:

)

Your answerChoose one option.

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Let

and

denote the energy eigenstates of a one-dimensional simple harmonic oscillator. The position and momentum operators are

and

, respectively. The matrix element

is non-zero when

Your answerChoose one option.

only

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A two-level quantum system has energy eigenvalues

and

. A perturbing potential

is introduced, where

is a constant having dimensions of energy,

is a small dimensionless parameter, and

. The magnitudes of the first and the second order corrections to

due to

, respectively, are

Your answerChoose one option.

and

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An electron with mass

and charge

is in the spin up state

at time

. A constant magnetic field is applied along the

-axis,

, where

is a constant. The Hamiltonian of the system is

, where

and

. The minimum time after which the electron will be in the spin down state along the

-axis, i.e.,

, is

Your answerChoose one option.

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GATE PH kind:question PYQs

Question 36

Question 37

Question 38

Question 39

Question 40

Question 41

Question 42

Question 43

Question 44

Question 45